1. Field of the Invention
This invention relates to closure fasteners, more particularly to a manually operated latch for a single or double hung tilt window, which provides a snap tilt lock, sash lock, and vent lock for the window.
2. Description of the Prior Art
Latches for tilt windows generally include a spring biased bolt for engaging the jamb. Often the bolt head is beveled to force the bolt back when the window is rotated into the jamb whereupon the bolt snaps back into locking engagement with the jamb when the sash is rotated fully back into the jamb. Either a protruding or a recessed finger grip is provided for drawing the bolt back to release the bolt from locking engagement with the jamb so that the sash may be rotated out from the jamb.
U.S.P.N. 4,400,026 patented by J. M. Brown, Jr., Aug. 23, 1983 describes a tilt latch which includes a base for mounting on a sash by means of a screw through a screw hole that is located in the base, near the rear end of the base.
The base includes parallel side walls. A generally flat slide member is received in grooves in the side walls, for sliding to an extended locking position wherein a nose portion of the slide member extending over the front end of the base engages the jamb.
A spring is disposed between the base member and the slide member in a recess cooperatively defined by portions of the underside of the slide member and the upwardly facing surface of the base member. The spring is compressed between one end of the recess in the slide member and the head of the screw which holds the base on the sash, and biases the slide member toward the extended position.
Travel of the slide member to the extended locking position is limited by a downward directed ledge at the rear of the slide member, which engages the rear end of the base member.
A rearward portion of the slide member is resiliently deformable so that the rear end of the slide member can be pulled up, clearing the ledge from interference with the rear end of the base member. This permits moving the slide member in a direction of further extension in order to reveal the mounting screw in the base for mounting the tilt latch assembly on the frame.
U.S.P.N. 4,553,353, patented Nov. 19, 1985 by H. Simpson describes a pivotal window sash latch assembly which is mounted internally of the sash frame top. The latch includes a bolt for locking against window rotation by engaging the jamb. The bolt is slidingly clipped to the underside of a housing by flanges that extend below the housing.
An opening in the housing clears the way for fingers of a top mounted slider button which extend down through the opening to engage an opening in the slider for moving the bolt between extended and retracted positions. When the latch is installed in a sash, the housing is recessed into the sash with only the button extending above the top surface of the sash.
A spring for biasing the bolt in the direction of extension is located in a compartment in the bolt and bears at one end upon an abutting post which extends down from the housing, and at the other end in the direction of extension upon a wall of the compartment.
An elongated hole is provided in the slider to provide clearance for a mounting screw which passes down from the housing into the sash.
In U.S.P.N. 4,837,975, patented Jun. 13, 1989, H. Simpson describes an externally mounted latch for a pivotable sash window of a double-hung sash window assembly. The latch includes a housing including a rear and two downward depending side walls. A first downward extending post attached to the rear end side wall of the housing, has a through hole for attaching the housing to a sash. A second downward extending post located on the midline of the housing and spaced from an open front end of the housing also includes a through hole for attaching the housing to the sash.
Each side wall includes a short inwardly directed slider bearing segment for guiding the rear portion of a slider bolt which is retained under the housing by a retainer bar integral with the lower end of the second post. The second post passes through an elongated opening in the bolt, and the retainer bar traverses under the slider bolt, extending in the direction of the rear wall.
A spring for biasing the bolt toward the open end of the housing for locking engagement with a window jamb, is contained at one end by a wing portion of the bolt which extends from one side of the bolt near the front of the bolt, to a side wall. Another wing portion extends from the other side of the bolt, near the front of the bolt, to the other side wall.
The other end of the spring engages a spring stop pin which extends from one of the side wall slider bearing segments, in the direction of the open front end of the housing.